In such an X-ray inspection apparatus, an X-ray detector such as a cassette, CR (Computed Radiography), or FPD (Flat Panel Detector) is used. In the X-ray inspection apparatus that photographs a subject in an upright position state, such as an upright position stand type, depending on a physical constitute of the subject or a subject's site to be photographed, a vertical position of the X-ray detector is changed and along with this, a vertical position of an X-ray tube is also changed.
The X-ray detector is contained in an X-ray detector containing part such as a bucky part. The X-ray detector containing part is configured to be able to contain any of X-ray detectors having various sizes other than an X-ray detector having a size corresponding to the X-ray detector containing part. When the X-ray detector is attached to the X-ray detector containing part, a reference position thereof is determined by upper reference based on an upper end of the X-ray detector containing part, center reference based on the center of the X-ray detector containing part, or lower reference based on a lower end of the X-ray detector containing part, and thereby the X-ray detector is configured to be mechanically fixed with use of a spring or the like. Any of such reference positions is conventionally determined in an unambiguous manner in association with mechanical structure of each X-ray detector containing part (see Patent Literature 1).
Also, for such an X-ray inspection apparatus, there is proposed a photography system that uses an anatomical program having data structure that relates a photographing condition, a subject' site to be photographed, a photographing method, and the like to one another, and according to the anatomical program and the like, automatically moves the X-ray tube to a photographing position (see Patent Literature 2). Further, the photographing position of the X-ray tube is calculated on the basis of a size of the X-ray detector and the reference position of the X-ray detector, such as the upper reference, center reference, or lower reference (see Patent Literature 3).